全文获取类型
收费全文 | 10275篇 |
免费 | 160篇 |
国内免费 | 86篇 |
专业分类
安全科学 | 399篇 |
废物处理 | 463篇 |
环保管理 | 1665篇 |
综合类 | 1348篇 |
基础理论 | 2646篇 |
环境理论 | 9篇 |
污染及防治 | 2327篇 |
评价与监测 | 704篇 |
社会与环境 | 879篇 |
灾害及防治 | 81篇 |
出版年
2023年 | 77篇 |
2022年 | 120篇 |
2021年 | 111篇 |
2020年 | 90篇 |
2019年 | 107篇 |
2018年 | 193篇 |
2017年 | 219篇 |
2016年 | 288篇 |
2015年 | 187篇 |
2014年 | 303篇 |
2013年 | 817篇 |
2012年 | 393篇 |
2011年 | 540篇 |
2010年 | 413篇 |
2009年 | 450篇 |
2008年 | 505篇 |
2007年 | 503篇 |
2006年 | 465篇 |
2005年 | 396篇 |
2004年 | 367篇 |
2003年 | 360篇 |
2002年 | 315篇 |
2001年 | 337篇 |
2000年 | 253篇 |
1999年 | 168篇 |
1998年 | 114篇 |
1997年 | 116篇 |
1996年 | 115篇 |
1995年 | 139篇 |
1994年 | 137篇 |
1993年 | 122篇 |
1992年 | 115篇 |
1991年 | 100篇 |
1990年 | 101篇 |
1989年 | 88篇 |
1988年 | 88篇 |
1987年 | 93篇 |
1986年 | 96篇 |
1985年 | 80篇 |
1984年 | 90篇 |
1983年 | 90篇 |
1982年 | 100篇 |
1981年 | 68篇 |
1980年 | 61篇 |
1979年 | 47篇 |
1978年 | 58篇 |
1977年 | 44篇 |
1976年 | 40篇 |
1974年 | 36篇 |
1972年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
141.
142.
IntroductionBecauseofthelowefficiencyoftheelectrostaticprecipitator (ESP)forcollectingthesubmicronparticles ,theelectricalagglomerationmethodhasledtoanincreasinginterestinreducingtheemissionofthefineparticles .Manyauthorshavestudiedelectricalagglomerati… 相似文献
143.
144.
Linda?Anderson-BerryEmail author David?King 《Mitigation and Adaptation Strategies for Global Change》2005,10(3):367-392
Community mitigation of hazard impact requires hazard knowledge and preparedness on the part of the members of diverse and
complex communities. Longitudinal research in the tropical cyclone prone north of Australia has gathered extensive datasets
on community awareness, preparedness and knowledge, in order to contribute to education campaigns and mitigation strategies.
Data have been used to identify issues of vulnerability to cyclones and capacity to deal with the hazard. This has been developed
as a community vulnerability and capacity model that may be applied to diverse communities in order to assess levels of capability
to mitigate and deal with the cyclone hazard. The model is presented here in a simplified form as its development is evolving
and ongoing. 相似文献
145.
Three cases of unusual chromosomal mosaicism are reported for which the cytogenetic data show inconsistent findings between CVS and AC or fetal tissue, and which cannot be explained simply by non-disjunction. For case 1, in CVS the karyotype was 46,XY, whereas lymphocytes and fibroblasts revealed 69,XXY. DNA fingerprinting indicated one paternal and two maternal chromosome sets, the latter most probably due to omission of maternal meiosis II. For case 2, in CVS mos 46,XX/47,XX,+mar de novo was observed. Amniotic fluid cells had the karyotype 46,XX. The origin of the marker chromosome might be explained by at least two events of unknown order (a somatic chromosome/chromatid deletion and non-disjunction of the homologous chromosome). In case 3 (CVS: mos 46,XY/46,XY,19q+ de novo; amniotic fluid cells, lymphocytes, and fibroblasts: 46,XY), the surplus of chromosome material in 19q+ might be explained on the basis of a somatic translocation. The idea of a chimera is less convincing, as the mosaic finding is restricted to one tissue. Furthermore, there was no hint of a vanishing twin. Hitherto, no case of structural chromosome mosaicism in CVS has been reconfirmed in fetal tissues. 相似文献
146.
Maguelone G. Forest Hervé Bétuel Philippe Couillin André Boué Michel David Daniel Floret René Francois Pierre Guibaud Henri Plauchu Raphaël Rappaport 《黑龙江环境通报》1981,1(3):197-207
Amniotic fluid (AF) levels of 17-hydroxyprogesterone (17OHP) and testosterone (T) were determined at 16–17 weeks in 17 pregnancies at risk for CAH and results compared to 75 normal controls. The fetus was predicted to be unaffected in 12 cases on the findings of normal AF levels of both 17OHP and T and the latter allowed a correct prediction of fetal sex in all instances. HLA typing confirmed normality in 12 cases revealing 5 carriers, 5 homozygous normal and 2 indeterminate. Steroid levels of the 2 groups were similar. Three fetuses were predicted to be CAH affected on unambiguously high levels of 17OHP and T (in female only). HLA typing was in agreement, and the diagnosis was confirmed in 2 abortuses and a female newborn by physical and hormonal studies. In the last 2 cases AF levels of OHP and T were normal but HLA (A/B/C) genotypes were identical to the CAH affected siblings. Normal physical and hormonal findings in the 2 aborted fetuses would exclude the possibility of an in utero virilizing form of CAH. The discrepancy could be explained on the basis that the fetuses had an allelic form of 21-hydroxylase deficiency or on the basis of recombination (not fully tested). It is concluded that a fully informative prenatal diagnosis of CAH should not rely entirely on HLA typing but on hormonal studies. 相似文献
147.
148.
Circulating placental [human chorionic gonadotrophin (hCG), Schwangerschafts protein 1 (SP1), pregnancy-associated plasma protein A (PAPP-A), decidual (pregnancy protein) 12 (PP12), and fetal alphafetoprotein (AFP)] proteins were measured immediately before and within 1 h in 18 women undergoing diagnostic chorionic villus sampling (CVS) in the first trimester. An elevation of serum AFP levels was consistently seen, while fluctuations in excess of 10 per cent of the pre-CVS levels of SP1 and PP12 were seen in the majority of patients. Fluctuations in hCG and PAPP-A were consistently less than 10 per cent of pre-CVS values. Post-CVS changes in levels were not apparently associated with any feature of the technique, the pregnancy, or its outcome (one missed abortion). As feto-maternal haemorrhage is a common event, anti-D should be offered to rhesus-negative women undergoing CVS. In the prediction of subsequent miscarriage, only hCG and PAPP-A measurements should be considered. 相似文献
149.
150.